Electric condenser and process of making the same.



M. MEI ROWSKY.

' ELECTRIC CONDENSER AND PROCESS OF MAKlNG THE SAME.

APPLHCATION FILED NOV. 30. I914.

I Patented Feb. 29, 1916.

MAX I MEIROWSKY, 0F PORZ-ON-THE-RHINE, .GERMANY.

ELECTRIC CONDENSER AND PROCESS OF MAKING THE SAME.

Specification of Letters Patent.

Patented Feb. 29, 1916.

Application filed November 30, 1914. Serial No. 874,893.

To all whom it may concern:

Be it known that 1, MAX MEIROWSKY, subject of the King of Prussia,German Emperor, residing at Porz-on-the-Rhine, Germany, have inventedcertain new and useful Improvements in Electric Condensers and Processesof Making the Same, of which the following is a specification, referencebeing had therein to the accompanying drawing.

My invention relates to electric condensers and to a process of makingthe same.

It has heretofore been proposed to make plate-shaped condensers byimpregnating paper with resin, oil, parafiin or other impregnatingagents and, after inserting the requisite metallic layers,.-:compressing the same in a press, heat being applied in certain cases.Condensers made in this manner have, however, series defects.

Resin, oil, paraffin and the like are substances which soften atmoderate temperatures. Therefore the material may be subjected to onlyrelatively slight stresses.

WVhen stressed severely the temperature rises more and more and thedielectric is finally punctured. Paraffin softens at a temperature ofabout 40 C. and resin at about 60 C.

In addition, the substances adapted for the purpose mentioned arehygroscopic. Paraffin possesses a relatively small adhesive ca pacity.Consequently the individual layers are not intimately connectedtogether, and can be lifted one from another after being compressed. Insuch a condenser very thin layers of air between the individual layerscannot be avoided, and such a condenser therefore causes considerablenoise, when it is subjected to a difference of potential, and it is alsoheated considerably. The penetration of air into ready-made condenserscan also not be avoided. Consequently it has heretofore been customaryto immerse such condensers in an oil-bath or to cast a suitable massaround them in order to protect them from moisture or mechanical forces.Further, they are provided for the same purpose with a casing ofsheet-metal or wood. All these protective devices are complicated andmost of them are insuflicient. For example, it may be mentioned thatwater is liberated from the oil, and electric conductors have to bepassed through the oil-bath. It has also been proposed heretofore toemploy as an impregnating and binding agent for the dielectric asynthetic resin, particularly a condensation product from phenols andformaldehyde. Synthetic resin, however, in its original state, in whichit is used for impregnation, contains a high percentage of alkalis andother substances which are still in it when it is employed. Thesesubstances render synthetic resin almost unusable for a condenser.

A primary object of my invention is to obviate the injurious action ofthe alkalis and other disturbing substances in synthetic resin used incondensers. To this end I make the dielectric of alternate layers ofpaper and synthetic resin consolidated or welded together. For example,well glazed paper is coated with the resin material. This material canbe dried by exposing it to a suitable temperature before its insertioninto the press, so that sheets of paper having a dry layer of syntheticresin are obtained. A suitable number of these sheets arranged with therequisite layers of metal arranged between them are consolidated bymeans of severe pressure in a press, whereby the synthetic resinundergoes the known process of conversion under the influence ofpressure and heat. The alkalis or the like still contained in the layersof resin in spite of the preliminary drying operation constitute nodanger because the layers of resin, which in section under themicroscope can be clearly distinguished from the layers of paper, areconnected with the latter in series and are subjected to no considerabledifferences of potential.

The condenser made in this manner has an exceeding great resistance tomoisture and is very refractory. The individual layers are so intimatelyconnected together under the high pressure in the press that it isimpossible for air or moisture to penetrate between them. The condenserhas a solid structure like that of the hardest wood and, accordingly,can be worked on machinetools and be otherwise used in the art. It isnot necessary to provide it by means of paraffin, oil or some othermoldable or impregnating material with a protective casing, as is thecase with ordinary condensers. It has a rigid structure and resists themaximum stresses to which it is subjected in practice, because thedielectric not only carries the electrically conducting intermediatelayers, but at the same time imparts to the condenser its internal andexternal stability. Owing to air spaces no longer being able to occur itis also possible to make condensers of the type described for thehighest voltages.

Condensers for testing-voltages of 260,000..

volts have already been made and there is no doubt that the voltageitself need not be .kept within any practical limits, While the.maximumivoltage of plate-shaped condensers impregnated with paraffin orresin may not exceed 800 to 900 volts. Consequently it is possibletomake plate-shaped high tension condensers. Another advantage of my-limprovedc condensers is that they can be employed in moist air becausethey are only slightly hygroscopic.

In the accompanying drawing :Figure j 1 is a cross-section, enlarged,taken on the line A-B in Fig. 2 or Fig. 3 through a'condenser madeaccording to the hereindescribed process, Fig. 2 shows an improvedcondenser having the well-known external form of a plate-shapedcondenser, and Fig.

3 is an end elevation of an improved condenser having the form of thewell-known tubular condenser.

'. .Referringto the drawing, the'layers of I paper are designated a,-thelayers-oiiresin1),

and the metallic'layers c.-

Having nowqparticularly described and ascertained the mature ofmy saidinvention condenser consisting in coating glazed paper withsyntheticresin, drying said coating of resin, applying plates of metalalternately with the sheets of resin coated glazed paper andconsolidating said glazed paper and resin, with said metallic plates bysubjecting the same to the action of pressure and heat.

In testimony whereof I have affixedmy signature in the presence of twowitnesses.

MAX MEIROWSKY.

' Witnesses J. WIJNEN, J. D. ZIESJECKY.

